Direction indicator for moving bodies



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p 927 T. ROSENBAUM DIRECTION INDICATOR FOR MOVING BODIES Filed July 15, 1924 Patented Sept. '13, 1927.

UNITED STATES PATENT OFFICE.

THEODOR ROSENBAUM,- OF BERLIN, GERMANY; SELMA ROSENIBAUK AND ILSE ANNA IA'I'HILDE BOSENBAUM, SOLE HEIRS OF SAID THEODOR ROSENBAUM, DECEASED, ASSIGNOBS T GYRORECTOR GESELLSCHAFT MIT BESCHRANKTEB HAETUNG, O1

BERLIN, GERMANY.

DIRECTION INDICATOR FOR MOVING BODIES.

Application filed July 15, 1924, Serial No. 726,228, and in Germany July 1:, 1m.

This invention relates to improvements in direction and curve indicators for moving bodies, such as aircraft and the like, comprising a gyroscope rotatrngun a vertical 5 plane andin which the lndicator is provided in the known manner with an ndicating device, and the supportot the gyroscope is mounted in a frame rotatable about a horizontal axis.

The invention has for its object to reduce in such an indicator the amplitude of oscillations. of the vertical direction indicator about its horizontal axis by utilizing the precession movements of the gyroscope about its vertical axis for operating electric contacts by means of which an electric reversible motor engaging with the vertlcal rectangular frame is driven in one or the other direction, according to the directlon of precessional rotation, and thus is put in a POSI- tion at once to counteract any impulses acting on the vertical direction indicator.

Such a device howeverfor which will be explained later on-presents the disadvantage that after curved flights which are performed with the machine longitudinally inclined, the' vertical dlrection indicator is forced by the electric motor to deviate from its correct position. avoid that, according to the invention provision is made whereby the vertical direction indicator, is free to move relatively to the horizontal transverse axis of the system with the object of avoiding incorrect positions after such curved flights. Moreover according to the invention the indicator can be given, by shifting its centre of gravity, an oblique position in the vertical longitudinal plane of the machine, owing to which deviations from the course caused in any way, can be ascertained from the indications given by the indicator, and exactly corrected.

Rela devices'based on the principle of a reversi le motor, have already been repeatedly used for stabilizing gyroscopes. The reversible electric motor according to the invention differs from known devices by the special object for which it is intended, and by its action. The working of the reversible motor used in the invention is that, firstly, the electromagnetic excitation of the reasons motor is definitely fixed by the precessions which the gyroscope makes relatively to the system on which it is mounted with its precession spindle, and secondly, that the motor imparts to the system suspended like a true pendulum, the property of swinging at once into the position of equilibrium without oscillating about the second position, that is to say as the pendulum approaches the said position of equilibrium the motion becomes slower instead of faster as in an ordinary pendulum. As regards the special object for which the reversible motor is intended, it is, as already stated, to increase the accuracy of the indications pf a gyroscopic apparatus acting as a plumb Two constructions according to the invention are illustrated by way of example in the accompan drawing in which Figure 1 s ows the first construction in side elevation,

Figure 2 the contact and current supply device in plan,

Figure 3 the resilient arrangement of the contact pins and Figures 46 the second construction in side elevation, from elevation and plan.

a is the su port of the rectangular frame I), 0 the horizontal spindle, on which the frame I) is pivoted in the support a, so that the pending spindle 0 is substantially parallel with the longitudinal axis of the actuated member or the direction in which it moves. d the gyroscope, e the gyroscope support pivoted in the frame 6 for precession about the vertical axis and f the pointer mounted on the spindle 0. Above the frame I) to the gyroscope support 0 is attached a lever g Wl'llCh together with the gyroscope (Z travels to and fro between the contact pins h, i, k.

and Z (Figure 2) and in that way supplies current to the motor m from the source of current n through the contact pins 0 and p with which it is provided. The supply of current is efiected in such a manner that, according to the direction of the precession motion, the motor m is driven in one or in the other direction. The contact pin it is shown in Figure 3 by way of example on an enlarged scale with its guide tube B fitted into its bearing block A, and with the helical spring C acting in the said tube as a buffer, in order to better show the resilient arrangement of the contact pins. On the left of the current generator n is shown a sw1tch g b means of which the supply of current to tli e contact pins 72., 2', k and Z can be cut off.

Corresponding letters primed refer to similar parts in Figs. 4-6 as in Figs. 1 and 2. The support a is freely mounted in an outer support 8 by means of a splndle r so that the second pending axis or spindle 1' of the frame a is parallel with the transverse ax s of the actuated member. To the spring 1' 1s connected a toothed wheel segment t which transmits at a high ratio the movementsof the support a to the addle wheel at which is enclosed in a drum 'lled with glycerine or some other dam ing liquid.

The effect of t e motor is as follows. The

.- gyroscope d, in counteracting the impulses acting on its spindle c-by precessions about its vertical axis and thereby in bringing the contact pins 0 and p either against the con tacts h and Z or the contacts is and i, closes the circuit leading from the generator n to the motor, now in one and now in another direction of current, and in that way releases a counter-impulse equal to the primary impulse. As soon as the counter imulse has reached the value of the prlmary lmpulse, the gyroscope a? must again swing back and thus release the contacts closed by it. The principle of the arrangements made is therefore that the gyroscope counteracts the impulses acting on it, not by gyrostatlc ressures, that is to say not by continuously moreasing precessions but merely by controlling the motor.

The gyroscope acts in consequence of a rotary moment about the axis 0 by an advanced movement or precession about the vertical axis g, and this advance movement or precession closes both contacts 2', k or k, Z, and thereby actuates the auxiliary motor m which counteracts the first mentioned moment about the axis 0. The instrument shows the lateral inclination, namely the rolling angle and not the rolling movement, relative to a true perpendicular line by means of the gyrosco e which is suspended like a pendulum; it rther shows the lateral inclination relative to the seemingly perpendicular line by means of a pendulum. Since the true and the seemingly perpendicular lines differ substantially from each other in the turning movements, the straddle, or angle of division, of the two perpendicular lines offers a measure for the rate of speed in turning a secondary effect.

In order to make clear the advantage offered by the provision of a new degree of freedom obtained by the arrangement of the spindle 1-, it is first necessary to consider the following:

When that transverse plane of the gyroscope device which is determined, on the one hand, by the gyroscope axis, and on the other hand by the precession axis of the gyroscope, is exactly perpendicular, which in the construction shown in Figure 5 is attained by the mobility of the support a to the spindle 7' even in the case of longitudinal inclination of the aircraft, the gyroscope plane also must always remain veigtical owin to the arrangements made, without being a ected by the longitudinal inclinations of the machine and by its movements in curves. If however on the contrary the support a is given an angular elevation of 90 to the spindle 1', so that the precession axis of the gyroscope is directed horizontally, then in the case of a curved flight of the aircraft, the indicator f which is now also horizontal, must be held fast in its given position,

and therefore after a curved flight of the angle a, deviate from the direction of the true vertical line to the extent of the same angle a when the support a is again brought back to its vertical position. The consequence therefore must be that with an elevat1on position of the support a of an angle [3, the vertical position indicator 7 will be forced by a curved flight of the angle a to deviate from the perpendicular. line.

This gives the possibility of correcting in a simple manner deviations from the.

course. If opposite the vertical direction indicator f a pendulum is placed freely movable about the spindle 0 the angular elevation provided will make it possible to ensure that any deviation from the course would result in a scissors position of the two direction indicators, which position will remain until the machine has been brought back to its correct course. Thus deviations from the horizontal direct-ion can be corrected even without a compass.

The next utilization of the degree of freedom given to the support a relatively to the spindle 1', would be that the tendency to deviate expressed by the angle a sin B would be completely eliminated by giving the support a an exactly Vertical suspension by a suitable arrangement of the centre of gravity.

Having now particularly described and ascertained the nature-of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a direction and curve indicator for moving bodies, a gyroscope, a frame rotatable about a horizontal axis, a support for the gyroscope rotatable about a vertical axis in the frame, a circuit, a source of electromotive force interposedin the circuit, a reversible electric motor connected with the frame and interposed in the circuit, and coacting circuit controlling means in said circuit including groups of contact elements carried respectively by the frame and support.

2. In a direction and curve indicator for moving bodies, a gyroscope, a support, means for mounting the support for rotation about a horizontal axis, a frame, means for mounting the frame in said support for rotating about a horizontal axis which is at right angles to the support axis, a second support for the gyroscope rotatable about the vertical axis in the said frame, a motor on the support connected to oscillate the said frame, a circuit, a source of electro-motive force interposed in the circuit, and a pole changing device for the motor in said circuit including groups of contacting elements carried respectively by the frame and the second named support.

3. A direction and curve indicator for moving bodies including a gyroscope, a support means for mounting the support for rotation about a horizontal axis, a frame, means for mounting the frame in said support for rotation about a horizontal axis which isat right angles to the support axis said frame being pendulously mounted, a pendulum freely swinging about the last-named axis, a second support for the gyroscope rotatable about the vertical axis in the frame, a motor on the support connected to oscillate said frame about its axis, a circuit for said motor, a source of electromotive force interposed in the circuit, and motor controlling means. in the circuit including groups of contacting elements carried respectively by the frame and the second named-support to be closed by relative movement therebetween.

4. A direction and curve indicator as claimed, in claim 1, wherein a. second named support is provided for the frame and is movable about a horizontal axis at right angles to the frame axis so that deviations of the vertical direct-ion indicator are avoided even when the machine describes curves inlongitudinally oblique position.

In testimony whereof I hereunto aflix my signature. I

THEODOR ROSENBAUM. 

